19-K - 39

 19-K - 39 FUJI E.C.  EVAL-MAY87 H.NAKAMURA                       
                      DIST-MAR02 REV3-MAY01            20010517   
----JENDL-3.3         MATERIAL 1925                               
-----INCIDENT NEUTRON DATA                                        
------ENDF-6 FORMAT                                               
                                                                  
HISTORY                                                           
87-05  Newly evaluated by H.Nakamura (fuji electric co. ltd.)     
94-02  JENDL-3.2                                                  
       Total cross section was calculated by T. Watanabe (khi).   
       Inelastic scattering cross sections were calculated by     
       K.Shibata (jaeri).                                         
       Data were compiled by K.Shibata.                           
*****  modified parts for JENDL-3.2 ****************************  
(3,1),(3,4),(3,51-91),(3,251),(4,2),(4,51-54)                     
              new optical and statistical model cal.              
(3,2)         total - nonelastic                                  
****************************************************************  
01-04  JENDL-3.3                                                  
       Gamma-ray production data were evaluated and compiled      
       by K. Shibata                                              
*****  modified parts for JENDL-3.3 ****************************  
(1,451)            Updated                                        
(3,251)            Deleted.                                       
(4,2)              Transformation matrix deleted.                 
(5,16-91)          INT=22.                                        
(12,16-107)        Added.                                         
(14,16-107)        Added.                                         
(15,16-107)        Added.                                         
****************************************************************  
                                                                  
mf=1  General information                                         
     mt=451  Descriptive data and dictionary                      
                                                                  
mf=2 mt=151  Resonance parameters:                                
        Resolved resonances for MLBW formula: 1.0e-5 eV - 200 keV 
      Parameters are taken from BNL 325 4th edition/1/, and       
      some parameters are assumed to fit the measured data.       
      Cross sections calculated with these parameters are to      
      be corrected by adding mf=3, mt=1, 2 and 102 data.          
                                                                  
      calculated 2200-m/s cross sections and resonance integlals  
                                                                  
                     2200-m/sec   res.integ.   ref.               
          elastic      2.06 b         -         -                 
          capture      2.10 b        1.1 b     /1/                
          total        4.16 b         -         -                 
                                                                  
mf=3  Neutron cross sections                                      
     Below 200 kev                                                
        Background data for mt=1 : (mt=107)-cross sections.       
      mt=107 (n,a)=0.04 b (10**-5 eV), 0.0043 b (2200m/s)/1/,     
             int=5.                                               
     Above 200 keV                                                
      mt=1,2,4,51-54,91,102  Total, elastic, inelastic and capture
         Calculated with casthy code /2/, considering the         
       competition with the threshold reaction channels.          
       Optical potential parameters of C.Y.Fu/3/ are used.        
       The spherical optical potential parameters:                
            V = 46.72          Vso= 5.37    (MeV)                 
            Ws=  9.13          Wv = 0.0     (MeV)                 
            r =rso= 1.26       rs = 1.39    (fm)                  
            a =aso= 0.76       b  = 0.40    (fm)                  
      mt=102  Capture data are normalized to 4.2 mb at 200 keV.   
         The discrete level scheme taken from ref./4/:            
            no.      energy(MeV)     spin-parity                  
           (g.s)      0.0             3/2   +                     
             1        2.523           1/2   +                     
             2        2.814           7/2   -                     
             3        3.019           3/2   -                     
             4        3.598           9/2   -                     
       Continuum levels assumed above 3.8 MeV. The level          
       density parameters of Asano et al./5/ are used.            
    ***** JENDL-3.2 ********************************************  
    The total and inelastic scattering cross sections were cal-   
    culated by using the omp set determined by T. Watanabe.       
           V = 54.36 - 0.325En   (MeV)                            
           Ws= 2.258 + 0.1698En  (MeV)                            
           Vso=3.341             (MeV)                            
           r  =1.20  ,a  =0.658  (fm)                             
           rs =1.32  ,b  =0.602  (fm)                             
           rso=1.10  ,aso=0.406  (fm)                             
    The cross sections of mt=16,22,28,103,107 in JENDL-3.1 were   
    considered as the competing process for the statistical model 
    calculation.                                                  
    ************************************************************  
    200 keV - 1.0 MeV                                             
      mt=107 (n,a)-cross section = 2.6*10**-5 b (constant):       
         assumed from the calculated value at 1.0 MeV.            
    Above 1.0 MeV                                                 
      mt=16,22,28,103,107  (n,2n), (n,na), (n,np), (n,p), (n,a)   
         Based on the statistical model calculations with gnash   
       code/6/, without the precompound reaction correction.      
       transmission coefficients for proton and alpha particle    
       are calculated by using the omp of Becchetti-Greenlees     
       /7/ and Huizenga-Igo/8/, respectively.                     
       Level density parameters are based on built-in values.     
         At the energy range of 4 - 20 MeV, (n,p) cross section   
       was based on the experimental data/9-11/.                  
                                                                  
mf=4  Angular distributions of secondary neutrons                 
     mt=2  Calculated with optical model (casthy).                
     mt=51-54  Calculated with Hauser-Feshbach formula (casthy)   
     mt=16,22,28  Isotropic in the laboratory system.             
     mt=91        Isotropic distributions in cm were converted    
                  to the distributions in lab.                    
                                                                  
mf=5  Energy distributions of secondary neutrons                  
     mt=16,22,28,91,103,107  evaporation spectra.                 
                                                                  
mf=12 Photon production multiplicities                            
     mt=16,22,28,103,107                                          
       Multiplicities were calculated by using the egnash code    
       /12/.                                                      
     mt=102                                                       
       Multiplicities were calculated by using the casthy code    
       /2/.                                                       
     mt=51-54                                                     
       Transition probability arrays were given.                  
                                                                  
mf=14 Photon angular distributions                                
     mt=16,22,28,51-54,91,102,103,107                             
       Isotropic                                                  
                                                                  
mf=15 Continuous photon energy spectra                            
     mt=16,22,28,103,107                                          
       Multiplicities were calculated by using the egnash code    
       /12/.                                                      
     mt=102                                                       
       Multiplicities were calculated by using the casthy code    
       /2/.                                                       
References                                                        
 1) Mughabghab, S.F. et al.: Neutron cross section, Vol.1 (1981). 
 2) Igarasi, S.: J. Nucl. Sci. Tech., 12, 67 (1975).              
 3) Fu, C.Y.: Atom. Data and Nucl. Data Tables., 17, 127 (1976).  
 4) Lederer, C.M. et al.: Table of isotopes. 7th edit.            
 5) Asano et al.: private communication.                          
 6) Young, P.G. and  Arthur, E.D.: LA-6947 (1977).                
 7) Becchetti, Jr. and Greenlees, G.W.: Polarization phenomena    
   in nuclear reactions, p.682 (1971).                            
 8) Huizenga, Jr. and Igo, G.J.: Nucl. Phys., 29, 462 (1962).     
 9) Bass, R. et al.: Nucl. Phys., 56, 569 (1964).                 
10) Bormann, M. et al.: Zeitschrift f. Naturforschung, Section A, 
   15, 200 (1960).                                                
11) Aleksandrov,D.V. et al.: Atomnaya Energiya, 39(2), 137 (1975).
12) Yamamuro, N.: JAERI-M 90-006 (1990).